Process of making a stable hydrogen peroxide



1 UNITED S AT S (hereinafter referred to as a peroxide Patented May 3,1927.

ARTHUR L. HALVORSEN, OF PERTH AMBOY, JERSEY.

. V raocnss or'naxme savanna nxnnoonn rnnoxrnn.

Ito Drawing; I

portation, or storage for a considerable time, without notable loss of strength, and hence without material increase in cost, due to freight'charges and loss by decomposition in transit, per unit of consumers strength of product.v This process will, allow the manufacture to be carried out on a large scale at the most suitable place and theshipment of the product to be made' to any far away market of the world.

' Another objectis to providean alcoholicv solution of the hydrogen peroxide, which will find other .uses than the usual water solution of hydrogen peroxide, due to being soluble in some cases when thewater solution is not soluble or in cases where the presence of water 1s objectionable. J

- With these objects in view, the invention consists in causin reaction between a peroxidesuch as so mm or barium peroxide an alkali-formin metal) and an acid preferably in alcoho 1c solution, to form hydrogen peroxide and' the corresponding salt, separating the salt and solution which can be accomplished by filtration), a ding alco-. hol to the solution, if this should be re uired in orderto cause further separationo salt, removing any salt thus precipitated, by filtration, distilling the solution and making use of the marked differences in vapor tension between alcoholand hydrogen peroxide to obtain any desired division of weak and vezy strong'products.

sample 1.- -An amount of industrial alcohol, of say 90 to 95%, more or less, is preferably .cooled' to zero or lower. To each litres of alcohol I kilogramof concen- ,rated sulfuric acid (1.84 s. g. or so) is,

' added while cooling and stirring, and the mixture is cooled to zero or lower.. For each 4 kilograms of the acid 3 kilograms of sodium peroxide are then added, also under stirring and cooling. The temperature is preferabl kept at 0 C. or lower. There is none of t e violent reaction (with decomposition) so objectionable when water is used in place of alcohol for diluting the acid. The reaction progresses very gradually; .after all the sodium. peroxide has been added, the reaction may beaccelerated or used.

.Appllcation filed, m 2, 1921. Seria11io.482,1'i0.

retarded at willby regulating the temperature by means of the cooling equipment.

I prefer to keep the tem erature at not above 10 C. during the ear ier art of the reaction, after the sodium peroxi e has been added, but have experimentally allowedit to exceed 70 C. and even to approach the boiling point of alcohol, and have yet been able to quickly check the reaction and re duce the temperature by surface. cooling alone. Such high temperature is not at all desirable, however.

Considering any danger of violent fire or explosion, I have purposely lighted-the mixture, just at the time when the feeding of the sodium peroxide has been completed, and also in the middle of the feeding period. Only feeble,- fiickerin surface fires result, which are put out t e moment the open reaction vessel is covered up.

While in case of a water-acidmixture, a fine and floury kindof sodium peroxide is undesirable for the manufacture of hydro gen peroxide, because ofrits tendency to f cause high loss by decomposition, due to too sudden reaction before it becomes pro erly mixed with an adequate amount of aci underneath the surface of the solution, such sodium peroxide is very satisfactory and desirable when the alcohol-acid mixture is I finish the reaction with the mixture neutralor only slightly acid to litmus paper by adding towards the end a little more sodium peroxlde' or acid as may be required.

I separate from the solution the sodium sulfate which has been formed by the reaction this being effected by filtration and washing, which proceeds. freely and rapidly.

. In regard to, the bulk of the sodium sulfate to beremoved, it is. very much less than. in case of a corresponding water-acid reaction mixture, which is due probably to absence of water of crystallization and to the fact. that the thinner and'purer alcohol solution maybe removed fromthe salt more completely than the thicker and more impure water solution containing from 4 to 6 per cent of dissolved salt.

.I prefer to wash the se arated sodium sulfate with alcohol rather t an with water and to remove the last portions of the alcoholfrom the salt b heat, and can recover it as condensate, rea y for re-use for'alcoholacid mixture.

' product.

used for washin use? The sodium sulfate has a value as byjoin the alcohol, which has been the salt (or any desired.

fractions thereof with the bulk of the alcoholic hydrogen peroxide solution but pref- I -may erably excluding only-the'last fraction of wash, very weak in hydrogen peroxide,

f which I can re-use directly for making new alcohol-acid mixture, or forwashing a new lot of salt.

The alcoholic solution of hydrogen peroxide, now ready for distillation, may easily contain 60 to 80 grams H O per litre, depending on amount of wash used, and it contains onlya small amount of sodium sullatter half of the fate, corresponding to the slightsolubility of the salt in the alcoholic solution.

I distill the solution, preferably under reduced pressure to avoid unnecessary high temperature, and to be able to use steam in a suitable heating coil-or jacket as a source allow the vapors to leave the evaporator and enter the condenser together; very strong hydrogen peroxide solution condenses inthe' part of the condenser nearest the -evaporator; alcohol with a little hydrogen peroxide condenses. in the next part of the condenser; I withdraw the products separately. I avoid exposing the solution, which is to be distilled, to the heat (say about C.) for any needless length of time by feeding it into the evaporator only so fast as the evaporator is able to evaporate it, allowing no con-- about 510% of water, I reuse for alcohol acid mixture and for washing. This percentage figure for H 0 asreturned to the process for re-use, may be reduced by changes in the withdrawing of products from the condenser.

E rampze :2.--vraer and concentrated sul furic acid are mixed in the proportionv of 1 kilogram of acid to '3 litres of water,

and the mixture is cooled to zero C. or low'er.

Sodium peroxide is fed, gradually to. the

acid mixture under cooling and stirring until the mixture reacts neutral or very slightly acid against litmus paper. One or more times, usually once In the course of the to remove, by filtration, the sodium sulfate Which has been formedduring the reaction, in order to have a thinner mixture when I approach the finish; I may join this salt ieeding period I prefer" with the rest for the main filtration and washing treatment. The conversion is com-- plete practically as soon as the feeding of the sodium peroxide has been finished, the reaction being very vigorous throughout the period of feeding. It is preferable to keep the temperature down to. "10 0., though I have had it reach as high as 35 C. at times. 'At this higher temperature the loss by de-' composition is more serious.

I so arate a which has been ormed by the reaction,. from the solution by cooling to'() 'C.'or lower, filtering-and washing the salt with water,- joining any desired portion of the wash water with thesolutiom'excluding. only the weakest part, which I re-use for water-acid mixture or as a first-wash for another lot of salt.

The solution obtained contains from 4 to 6% sodium sulfate, a large'fraction of which being only slightly soluble in alcoholic solusiderable bulk of solution to accumulate in .tion, I remove before distilling by adding the evaporator at any time. I

The evaporator and condenser must not, of. course, be made of any material which prohibitively catalyzes the decomposition of hydrogen peroxide; but there is no" need of ficu lt to obtain a product with or more of H 0 per litre.

' eth n uslng acid-proof material, such as glass or quartz, the solution being neutral or nearly so. I preferably use tin (i. e. block tin or tin plate), or tin-antimonyalloy. I withdraw regularly only two separate products from the, two parts of the condenser, containing respectively, .say, about 350 gramsH O per litre, andefrom to 10 grams H O per litreyimd I obtain these' products in the ratio ofabout 1 to 5. 5

But I can readily vary strengths and ratios by sim 1e changes, and it is not dif- 500 grams The bulk of the alcohol, with the mall content of 1llilyzdrogen peroxide, representing e- 1 Qf% oithe total H,O ,sm1

up to as high as 5 litres alcohol (say 90 to %.stren'gthlper 10 litres of solution,cooling to 0 (3., or a few degrees lower, filtering'and washing. This second salt I do not unite directly with the rest of-the salt but add it instead. to the next finished re action mixture before the same is sub'ected to the main filtration treatment. T is is done to save any alcohol and hydrogen per.- oxidewhich may be in the second salt..

The solution of hydrogen peroxide, ready, .fordisti'llatiorr may contain about 60 grams H 0 and 5 grams dissolved salt per litre. If I use less wash water and alcohol, I get, more concentrated solution. used. any .very considerably less alcohol,

however,.the solution contains asomewhat' higher. ercentage oi salt, viz,with llitre of .alco 01 to 10 'litres water solution, 32

art of the sodium sulfatew It ,I have I grams salt per litre, with 2.5 litres alcohol to 10 litres water solution,.17 grams salt'per litre,- w ith I 5 litres alcohol-to 10 litres, water solution, grams salt per. litre. I I prefer not .to use any less than 3.5 litresalcphol to litres of watersolution.

' I distill under -reducedpressure as before,

and I withdrawt'wo or. more separate, fractions from the condenser. YI 'do not obtain, however, thesame sharp and easy 'fractiona- -tion, and .I prefer'to make a product with i ,only 100to IlO'grams H O per litre. The a weak fraction may contain under these con- 'iditi'ons of running, not over 10 grams H O may be returned tothe process, as the alcoper litre, and practically all-the alcohol, and

holfo'r addition to thenext bath, or part 'ofthis may be added to the stronger solul.

- tionto make a uniform product, of somewhat lower strengthffor the trade. I may obtain the fractions in the proportion ofi It'is, of course, 5

' portions for .the

about-1 to 1'. To get stronger solutions of hydrogen peroxideb'y this method of procedure, I find it advantageous to fractiormte' into more'thanfltwoproducts to'obtain a smaller part of. the total H Ol 'in the" form of solution with 350 grams or more of H 0," per litre, and the-balance as weaker prod; ucts. This necessity is due to the fact that the vapors of hydrogen peroxide, alcohol and water may not be fractionatedwith the same ease as the vapors of hydrogenperox ide and alcohol aloneQ 'I have described procedures with an alco-Q I hol-acid mixture and with a'water-acid mixture for reaction and subse uent treatments ossible, 'i desired, to use alcohol wate'r-acid mixtures of varying proreaction and subsequent procedure.

H v H i I Hydrogen peroxide strengths inproducts of'the trade at present is;usu'allygiven as so and 'somany' volumes of pure oxygen gas, available, per one volume fof the solution,

- and is. simply termed Ifvolumes, 1 0'vol- ,umes, 12 volumes, etc;;""- The v tandard strength trade product'of 1O volumes/0on5 tainsabout 30 grams H O, per litre. The

strength terms used in nl yide'scription, 110', '350 and 500 grams of z O ip'er litre arev equivalenhto', respectively, about} 115 and .165 volumes. Referring to descriptiom-I can, ofcourse, 1 ffractionate, or mix the withdrawn fractions,

so that I. obtain alcoholic solutions of hy- [drogen peroxide of largely var ing strengths, in hydrogen peroxide as we 1 as alcohol. When .I-fuse the procedure described Exam le 1, -I prefer'to so withdraw and mix the ract'ions that I obtain a standard, uniform trade product containing 30% hydrogeniperoxide, 20% alcohol and 50% water, and to return the balance of the weak fraction, or fractionscontaining about 90% alcohol, tothe process for re-use, V Vhe n I -use th'e proceduredescribed in Example 2,

I prefer to so withdraw and mix the fractions that I obtain a standard, uniform (alcohol,

I (now Patent 1,536,213)

"into a mixture containing alcohol and sultrade roduct containing 6% hydrogen peroxi e,' 20% alcohol and the balance water. Such latter product even after keeping for some time, could be sold on a guar- I antee of 5% H 0 I can increase or. decrease the strength in peroxideas well as The nature of the method of production in itself guarantees uniform andextremely '75 high purity of the products, free of 'the residue and-acidity, etc., which have been found objectionable in hydrogen peroxide trade roducts of the past and which have .undou tedly considerably limited-their'value '80 and uses.

The strong and highly pure products should find new uses for medicinal purposes. With large scale roduction at reduced cost per unit of pro uct, the same can find many new industrial uses. i 1 do not herein claim-themethod of'con- "centrating H,Q solution by distillation 'f(n0r any especial principle-or, design of ap- -paratus. therefor) except when used inconuection .with the presence of alcohol in the liquid to be concentrated, such subject matterlforming the object'of a separate applicat on, Serial N 0. 483,424, filed July 9,1921,

. I claim: 1. A process of making hydrogen peroxide consisting in feeding a peroxide of ah alkali-forming metal intoa mixture containing alcohol and sulfuric acid, to form hydrogen peroxide solution and a sulfate, separating the sulfate and the solution by filtration, distilling the major part at least. of the. solution in ,a single operation and separately condensing from the vapors formed in such operation, a solution ric in hydrogen peroxide and another solution rich in alcohol. v 1 2. A process of-making hydrogen peroxide consisting in feeding sodium peroxide furic acid-to form hydrogen peroxide solution and sodium sulfate, separating the sodium. sulfate and solution distilling the ma or part at least of the solution in a single operation and separately condensing from the vapors formed in such operation a solution, rich in" hydrogen peroxideand another solution rich in alcohol.

f3. A process of making hydrogen per-' oxide; consisting. in feeding a peroxide of an alka-li-formlngmetal into a mixture of alcohol, water and sulfuric acid to form hydrogen peroxide solution and a sulfate, separating the sulfate and solution,-distill- 1 ng the major part at least of the solution in a 's ingle operation and separately con-' denslng from the vapors formed in such 'OPGI'iltIOII, a solution rich in h drogen oxide and'anot-her solution ric in alcoh li when .I haveany reason to iwisb; V 'todoso. Y

43A process of making hydrogen perox-f ide which comprises feeding a' peroxide of an alkali-forming metal into a, diluted acid toform hydrogen peroxide solution and analkali-forming metal salt of such acid, suchacid being one that does not substantially decompose hydrogen peroxide separating the hydrogen peroxide solution from salt formed, adding alcohol to such solution,

whereby at least the major part of any dissolved alkali-forming metal salt of the added acid is precipitated, separating such precipitated salt from the remaining solution I of hydrogen peroxide, distilling the major part at least of the solution in a single operation and separately condensing from the vapors formed'in such operation,

a solution rich in hydrogen peroxide and another solution rich in alcohol.

5. A-process of making hydrogen peroxide consisting in feeding sodium peroxlde into diluted sulfuric acid to form hydrogen peroxide solution and sodium sulfate, separating the sodium sulfate and solution, adding alcohol to the solution togprecipitate dissolved sodium sulfate, separating the precipitated sodium sulfate and the solution distilling the major part at least of the solu tion in a single operation and separately, 7'

condensing from the vapors formed in such operation, a solution rich in hydrogen 'peroxide and another solution rich in alcohol.

6. The process of making hydrogen peroxide which comprises feeding a peroxide of an alkaliforming metal into a mixture containing alcohol and an acid which will notcause decomposition, of the hydrogen peroxide solution, thereby forming hydro gen peroxide solutionand a salt of the acid used, separating the formed 'salt and the .solution from each other, and distilling the major part at least of the solution in a single operation and separately condensing from the vapors formed in such operation, a solution rich in hydrogen peroxide and another solution rich in alcohol.

7. In the production of hydrogen peroxide, the herein described step 1 the major part at leastof a quid mixture containing water, alcohol and hydrogenof distilling peroxide, in a single operation, and sepa rately condensing. from the vapors-formed in such operation, a mixture rich in hydrogen peroxide and another mixture rich ina lcohol. I p

In testimony whereof I aflix'my signature.

ARTHUR L.- HALVDRSEN, 

